Shamsie wrote her first novel, In The City by the Sea, while still in college, and it was published in 1998 when she was 25.[5] It was shortlisted for the John Llewellyn Rhys Prize in the UK,[6] and Shamsie received the Prime Minister's Award for Literature in Pakistan in 1999[4]. Her second novel, Salt and Saffron, followed in 2000, after which she was selected as one of Orange's 21 Writers of the 21st century.[4] Her third novel, Kartography (2002), received widespread critical acclaim and was shortlisted for the John Llewellyn Rhys award in the UK.[6] Both Kartography and her next novel, Broken Verses (2005), have won the Patras Bokhari Award from the Academy of Letters in Pakistan.[4] Her fifth novel Burnt Shadows (2009) was shortlisted for the Orange Prize for Fiction[6] and won an Anisfield-Wolf Book Award for fiction.[7]A God in Every Stone (2014) was shortlisted for the 2015 Walter Scott Prize[8] and the Baileys Women's Prize For Fiction.[9] Her seventh novel, Home Fire, was longlisted for the 2017 Booker Prize,[10] and in 2018 won the Women's Prize for Fiction.[11]

Shamsie states that she considers herself Muslim.[15] In 2007, she moved to London and is now a dual national of the UK and Pakistan.[1]

In 2012, she joined the latest incarnation of the Authors XIcricket team, despite never having played the game before. She contributed a chapter, "The Women's XI", to the book The Authors XI: A Season of English Cricket from Hackney to Hambledon (2013), collectively written by members of the team to chronicle their first season together.[16]